Summary of Award Activity for Stock Options Granted and Weighted Average Exercise Price Per Share (Detail) - $ / shares		12 Months Ended
		Dec. 31, 2016		Dec. 31, 2015	Dec. 31, 2014
Options
Options outstanding, beginning balance		800,000		612,500	412,500
Options issued		0		200,000	325,000
Options forfeited		(200,000)			(125,000)
Options exercised		0	[1]	0	0
Options expired				(12,500)
Options purchased by the Company		0		0	0
Options outstanding, ending balance		600,000		800,000	612,500
Options exercisable at December 31, 2016		450,000
Weighted Average Exercise Price Per Share
Weighted average exercise price per share, beginning balance		$ 25.94		$ 25.38	$ 18.62
Options issued				28.37	31.74
Options forfeited		28.37			19.60
Options exercised		0	[1]	0	0
Options expired				37.70
Options purchased by the Company		0		0	0
Weighted average exercise price per share, ending balance		25.13		$ 25.94	$ 25.38
Options exercisable at December 31, 2016	[1]	$ 22.71
Time Based Option Award
Options
Options outstanding, beginning balance		600,000		612,500	412,500
Options issued					325,000
Options forfeited					(125,000)
Options exercised		0		0	0
Options expired				(12,500)
Options purchased by the Company		0		0	0
Options outstanding, ending balance		600,000		600,000	612,500
Options exercisable at December 31, 2016		450,000
Performance Based Stock Options
Options
Options outstanding, beginning balance		200,000
Options issued				200,000
Options forfeited		(200,000)
Options exercised		0		0	0
Options purchased by the Company		0		0	0
Options outstanding, ending balance				200,000
Weighted Average Exercise Price Per Share
Options issued				$ 28.37
Options forfeited		$ 28.37

[1] The intrinsic value of the exercised options is the difference between the fair market value at time of exercise and the strike price of the option.